18 new and highly significant genetic markers for autism spectrum disorders has been discovered.
Researchers at the George Washington University School of Medicine and Health Sciences divided individuals with ASD into four subtypes according to similarity of symptoms and reanalyzing existing genome-wide genetic data on these individuals vs. controls.
In addition, ten of the variants were associated with more than one ASD subtype, providing partial replication of these genetic markers.
This study thus identifies candidate genes for ASD and potential subtype-dependent genetic markers for diagnostic screening.
The findings demonstrate the increased statistical power to identify significant genetic variants when subtyping reduces the heterogeneity of the samples tested and further begin to associate genotype with phenotype.
The researchers first identified genetic variants or single nucleotide polymorphisms (SNPs) that are associated with the degree of severity of various different autistic traits, and then they performed case-control genetic association analyses using these variants and subgroups of autistic individuals who share similar symptoms.
This helped the researchers to identify the 18 genetic markers that are associated with four subtypes of ASD, 10 of which were associated with more than one ASD subtype.
The study was recently published in the journal PLoS ONE.